This is a pretty simplistic explanation, because we have a contracting manager who does cartwheels to get the best reimbursement, and I wouldn't want his job.... But basically, first we contract with the payers to agree upon reimbursement model, typically based on a percentage of Medicare. For example, we might get 110% of Medicare for Anthem, and only 105% of Medicare for Cigna.
Then we price all of the charges at the same percentage based on our highest payer. So let's say our highest contract allows us 125% of Medicare, we'd price all of our fees to at least meet that percentage. Depending on whether you want to show large or small adjustments, you can set your fees accordingly.
You can see what Medicare reimburses for covered codes on the physician fee schedule.
http://www.cms.gov/apps/physician-fee-schedule/license-agreement.aspx
We charge everyone the same across the board, but do have financial aid available for those who cannot pay, and standard discounts for those who pay in full at the time of service. Also an 'employee discount'. If you decide to have those additional policies, get them in writing. The charge is always the same, but adjustments are taken for the discounts.